Engine starter gearing



Sept. 26, 1939. Y. sl-:KELLA 2,173,983

ENGINE STARTER GEARING Filed Jan. 5, 1938 Patented Sept. 2.6, 193gPATENT OFFICE 2,173,983 ENGINE STARTER GEARING Youston Sekella, ElmiraN. Y., assigner, by mesne assignments, to Bendix Aviation Corporation,South Bend, Ind., a corporation of Delaware Application January 5, 1938,Serial No. 183,500

3 Claims.

The present invention relates to engine starter gearing and moreparticularly to that type known as the manual shift in which amotor-driven pinion is moved by the operator into and out of mesh with amember such as a ywheel gear of the engine to be started.

In starter gearing of this type, it is customary to incorporate someform of overrunning clutch connection between the pinion and thestarting motor shaft so that when the engine starts, it may acceleratefreely Without transmitting its rotation to the starting motor. Varioustypes of overrunning clutches have been employed, but those in use havein general been subject to one or more of the objections that theyslipped, jammed, had excessive backlash, were noisy, harsh in action orexpensive.

It is an object of the present invention to provide a novel manual shiftstarter incorporating an overrunning connection which is positive inaction without undue shock, and free from jamming or Wedging.

It is another object to provide such a device in which the unitpressures on the parts are low, the operation is quiet and cushioned,and the structure is simple and inexpensive.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly in longitudinal section of a preferredembodiment of the present invention;

Fig. 2 isa section taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1; and

Fig. 4 is a view similar to Fig. l of a somewhat modified embodiment ofthe invention.

In the embodiment of the invention illustrated in Fig. 1, a motor shaftI which may be the extended armature shaft of a starting motor, notshown, is provided with a smooth portion 2 and a splined portion 3. Apinion 4 is slidably journalled on the smooth portion 2 of the motorshaft for longitudinal movement into and out of engagement with a membersuch as a flywheel gear 5 of an engine to be started, and a sleeve 6 isslidably keyed on the splined portion 3 of the shaft and provided withconnections for imparting its longitudinal movement to the pinion 4 andfor transmitting rotation from the motor shaft to the pinion.

According to the present invention, the connection between the sleeve 6and pinion 4 comprises a barrel member l xed in any suitable manner asindicated at 8 to the end of the pinion 4 and having splined therein atransmission disc 9. The disc 9 is normally located against a radialflange l I of a stop nut I2 threaded on the 5 end of the sleeve E, andis frictionally engaged by an elastic transmission member I3 in the formof a ring of rubber or similar material, which ring is adapted to becompressed against the disc 9 by means of a nut I4 threaded as indicated10 at l5 on the sleeve S. The pitch of the threads I5 is such that whenthe motor shaft I is rotated in the direction of the arrow, the nut I4will be caused to clamp the transmission ring I3 against the disc 9 andtransmit such rotation 15 thereto, but when the pinion 4 overruns themotor shaft, the nut I4 backs away and permits the pinion, barrel anddisc to overrun freely.

Perforations I6 and Il are preferably provided in the surfaces of thenut i4 and disc 9 contiguous 20 to the transmission member I3 in orderto increase the torque capacity of the transmission formed thereby. Inorder to facilitate the free overrunning of the disc with respect to thetransmission member, the latter is preferably anchored 25 to the nut I4by means such as the thimble I8 engaging the inner periphery of thetransmission member I3 and seated in a tapered groove I9 in the nut I4.

Means for insuring initial traversal of the nut 30 I4 into engagementwith the transmission member I3 is provided in the form of a frictionring 2| seated in a groove 22 in the periphery of the nut I4 and havingan outturned end 23 (Fig. 2) engaging in one ofthe spline slots 24formed 35 in the barrel l for the disc Il.

The parts of the transmission are retained in the barrel 1 by suitablemeans such as a split ring 25 seated in the interior of the barrel, anda spacing thimble 26 is preferably provided between 40 the disc 9 andthe retaining ring 25 in order toy cause longitudinal motion of thesleeve (i to be transmitted through the disc 9 to the barrel 'I withoutlost motion.

Shifting means for the sleeve 6 are provided 45 comprising a channeledcollar 27 mounted thereon and arranged to be engaged by any suitableform of shifting means, not illustrated. Longitudinal motion of thecollar 2l is transmitted to the sleeve E through a compression spring 28in 50 the usual manner, and a split ring 29 is seated on the end of thesleeve 6 for the purpose of retaining the shifting collar 21 thereon.

In the operation of this embodiment of the invention, the sleeve 6 withits associated parts is 55 caused to be moved longitudinally by theoperator until the pinion 4 meshes with the flywheel gear 5. Thestarting motor is then energized, causing rotation of the motor shaft Iand sleeve 6. The nut I4 does not immediately partake of this rotation,due to its frictional connection by the detent ring 2| with thebarrel 1. The nut is thus caused to compress the transmission member I3against the disc 9 until suii'cient pressure is built up to enable thetransmission member to rotate the pinion 4 through the disc 9 and barrelI and thus cause rotation of the engine member 5.

When the engine starts,l the overrunning action of the pinion 4 underthe impetus of the engine member causes the nut I4 and transmissionmember I3 to move away and release the disc 9 so that the pinion, barreland disc overrun freely until the pinion is withdrawn from mesh by theoperator.

In the structure illustrated in Fig. 4, the torque capacity of theconnection between the nut I4 and barrel I has been increased byrduplicating the transmission member I3 so as to form two suchconnections to the disc 9. As there shown, this is accomplished byinterposing a second transmission ring I I3 between the disc 9 and theange II of the stop nut,l2. This arrangement not only increases thetorque capacity of the coupling, but also is conducive to greaterquietness in action in that the disc 9 is cushioned with respect to thetransmission of shock therethrough in both directions. The remainingparts of the starting device are the same as those previously describedYand are similarly numbered.

It will be understood that inasmuch as the overrunning connection hereindisclosed is inherently capable of transmitting high torque without thenecessity of heavy axial pressure, the pitch of the threads I5 wherebysuch pressure is secured may be quite high so that the engaging actionis quickly secured, and release of the connection is rapid andunfailing.

Although but two embodiments of the invention have been shown anddescribed in detail, it will be understood that other embodiments arepossib-le and that various changes may be made in the design andarrangement of the parts without departing from the spirit oftheinvention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter, a shaft, a sleeve splined thereon, a pinionfreely journalled on the shaft for longitudinal movement intoY and outof engagement with a member of an engine to be started, a barrel memberfixed at one end to the pinion and surrounding one end oi the sleeve, astop nut rigidly anchored on the sleeve, a clutch member threaded on thesleeve, a clutch disc loosely mounted on the sleeve between the stop nutand clutch member and rigidly anchored in the barrel, a ring of elasticmaterial having a high coefficient of friction loosely mounted on thesleeve. adjacent said clutch disc, anda detent mounted on the clutchmember and splined in the barrel causing rotation of the sleeve toactuate the clutch member to clamp the ring and clutch disc against thestop nut.

2. In an engine starter, a shaft, a sleeve splined thereon, a pinionfreely journalled on the shaft for longitudinal movement into and out ofengagement with a member of an engine to be started, a barrel member xedat one end to the pinion and surrounding one end of the sleeve, a stopnut rigidly anchored on the sleeve, a clutch member threaded onvthesleeve,` aclutch disc loosely mounted onthe sleevebetween the stop nutand clutch member andrigidly anchored in the barrel, a ring of Velasticmaterialhaving a high coeiiicient of friction looselyA mounted on thesleeve adjacent said clutch disc, a detent mounted on the clutch memberYand splined in the barrel causing rotation 'of the sleeve-to actuate theclutch member to clamp the ring and clutch disc against the stop nut, ashift collar loosely mounted on the sleeve, and means for yieldinglytransmitting longitudinal movement from the shift collar to the sleeve.

3. In an engine starter, ashaft, a sleeve splined thereon, a pinionfreely'journalled on the shaft for longitudinal movement into and'out ofVen'- gagement with a memberof an engine to be started, a barrel memberXed at one end to the pinion surrounding one end of the sleeve andhaving a plurality'of longitudinal' slots extending from its free end, astop nut rigidly anchored on the end of the sleeve within the barrel, aclutch member threaded'on the sleeve, a clutch disc loosely mounted onthe sleeve between the stop nut and'clutch member 4having radialprojections tting in the slotsin the barrel, means including a sleevewithin the-barrel abutting the clutch disc for preventing longitudinalmovement of the disc in'the barrel, Aa ring of elastic material havingyahigh coeicient of frici tion loosely mounted on 'the sleeve adjacentsaid disc, said clutch member having aperipherall groove, and. a springring frictionally mounted in the groove and having a'projection slidablymounted in a slot of the barrel.

YOUSION iid

